Q. In APA, how do you cite a source that is referenced in the article or book you are reading?

Most citation styles discourage the use of a source that is found within the source your are reading. eg. if Smith (2011) quotes Jones' 1996 article, and you are only reading Smith's article, it is preferable to read Jones' article, then use that source. If you must cite Smith's reference to Jones, then do this: http://owl.english.purdue.edu/owl/resource/560/09/